Electric switch or circuit-breaker



G, A. BURNHAM.

ELECTRIC SWITCH 0R CIRCUT BREAKER.

AFPLICMIGN YILED APH-1.7, 1915.

G. A. BURNHAM.

ELECTRIG SWITCH 0R CIRCUIT BREAKER.

APPLICATION FILED APR. I7, 1916. e 1,337,995. Pmemed Apr. 27, i920.,

2 SHEETS-SHEET 2.

vin the current carrying' meinbere To all wlw/n t may Concern:

Be it known that I, GEORGE nniqifiii', e citizen of the Unitedl States, resiinng el; cl

tugns? in the county of Essen: and of hl; eeechnsetts, have invented en improve-- nient in Electric .Switches or Circuit-lineal;- ers` of which the following ie a specification.

@il switches end circuifbrefailers are usnnily cone'trnctecl in such nien?. that 'the bridgin -member will open, end l se th electric circuit which. 'the switch AUrolein e hath o1" oil contained in o suitable receptacle which7 for reasone of streng ln ie nenally of steel.

In switches oi' relativ y smell. carrying capacity, say 150G 2"!50 peres, no greet difficulty ie experiencecl in tlissipeting the heet which may be generated Cil T l loss in thc iron tai-,nir :nd the tcinpcrzitmre of the tenlc nitty rise to :L Very high velue. lt is posfiblc to lcsspcn such losses in the tenk by forming* it from :l noninegnetic motorini Such, for instance, ne brass. With Such u, tank, hmxcvcr, the initial cost is excessive; and, moreover.l (luc to the physical propertics of the `non-i'negnetic material employed, it cannot successfully Withstnnil the high preeenrc that may occur in the teni: upor the opening oi" the switch Mnl therefore it is exceedingly dceiroble to empioy :in oil reco/P- tsicle or teni; 'coi'istrnctctl of iron or steel.

is possible to reflnce iron loeses in the tenir by milking; the teni: oi" cerniere- 'tively great (limoni-sions, whereby the walls ."e tenir ere e, comparir." f tence e my from the cominotina other conlnctnig por-tiene oi'i "no whie i Sew@ to conduct nl, Such e constructie only w "if" auch Voir;

Serial No economically employe-cl. in any power etntion or on any switch board.

l have rliscovered that there is e relationship between the temperature or" the oil bath of n circuit breaker and the current which. can with safety be ruptured by the circuit breaker; 'that by restraining rise of tempereture oil' the oil beyond en empirically determined velue, the circuit breaker ceri safely rupture (and therefore carry While cioecl) nnich larger currents than can 'with safety l) rnptnreil if 'the temperature of e, oil is allowed to increasev as 1i'. Wil, ifi no temperatnre-reetreining or depressing means employed` Since it is not practical to reduce the hysteresis anal eddy current losses in the tructuro by lamine ngthe Walls there oi, is commen preo'aiee in electrical 'desigii, so111e ineens must. of necessity be proviclecl for iliesinnting the heat generated by such losses to thereby maintain to Some moderate value the temperature of the Wells of the tenir, which would otherwise rise to :in excessive velue.

oonsequently en instrumentality vfor carrying out my invention is in the provision of ineens for clissipating the heat generated in the Wells of the oil receptacle or tank of an oi ewitoh and so maintaining. the Walls :fini'l contained oil et a moderate temperature.

In accomplishing this object of my invention, liney employ en auxiliary cooling or radiating surface attached to thel Walls of the receptacle or tank in the form of fins, or integrally formed therewith, whereby the incrensecl total 'ndieting surface is suicient to dissipate the heet generated and so maintain the tenir or receptacle at a moderate temperature.

l may also provide the 'tank "with e jacket end circulate n. cooling medium such es air, oil7 or Water, for instance, therethrough, to nbfztmct the lient es rapidly as generated. 'll/he choice of the particular ineens employed to keep cool tl' e Walle of the 'tank and con seqnen 'f the oil in the 'tank will depend upon the particular coneitions under which 'the switch is required to operate.

ln case eir., or Writer, or other fluid is enr1 'nloye7 ore'er to canse it te pass through e only When predetermined conne or the rcnit exist, euch es en oyelQM ne current velue., in order that the eoolingmeens me; loe effective oniW at suchtime, hence l aise provide control ling-means for the cooling-means responsive toA such conditions.

Fi re l is a side eievetion ot' an nii switc 1 or circuit-breaker having cooiing means embodying this invention.

Fig. 2 is o. vertical section of sin nii-i taining receptacle and pipes eornecteci,thereN )with to form af ortion of n conduit :tor the lily of a coo ing-mediun'i.

'eng

. ig. 3 is a view of anoil switch und means for supplying a cooling medium, :in-'i for overning the deiivery of said cooling medium 'which is controlled by en overleed or other abnormai condition of the circuit.

Fig. 4 is a View of a. modification of my invention.

Referring to the dra-'wing i0 represents a. receptacle formed of a magnetic neteriei such es iron or steei :Ln-ii containing oilfin which ere submerged, the currentcnrryi components of any usufii or suitable i oil switch. Three receptacles are shown nl Figs. 1' and 3, and each has n, ciouhle willi, see Fig.l 2, thereby to form. :i space between the Walls which is preferably, although not necessarily, confined. Ti i space is adapted to form a part of n conduit through or along which there is caused to pass a cooling mediumusuch es :tir or Witter.

Une manner of carrying out my invention comJjpriSes pipes 20 and 2l connected to th'e receptacle in, open communication with the space 15, and air or Water from any suitable source is conducted through seid pipe 20 to the receptacles and caused to pass from the receptacles through the pipe 21,. The air or Water may be at or about reoxn tempereture or ower, and as it enters the space' 15,

it cools the Walls of the tenir or rebeptweie or prevents the temperature thereof from unduly rising and by thus cooling or. meintaining at a low temperature 'the wail of the receptacle the temperature oi the oil emi the current-carrying components is riso prevented from unduly rifing.

While it will be nel conditions to maintain the 'How oi stir or water continuously L through said conduit, yet it mlfy suffice to produce seid yfiow when predetermined conditions exist in the circuit, such for instance es an overload, hence n Veive 25 muy be connecteri in the pipe 50, oy which to control the (iow ci' eir or Weiter, end said Valve muy he controiletl by :in electro-magnet 26, connected. in e. circuit 2?, having a circuit-controller 28, 29, responsive to the energizetion oit a coii Si), which is :xrijusted and connected in the circuit so as to respond to the overleed. 1With this strueture the Valve is, openeti only upon fthe occurrence of an overload und is closed upon the cessation thereof. Good resuits, however, are produced hytlie employment oi' sable under some innige-e5 other n'Henne ic.' cooling the 'heat fiissipeti n nn, such for instance, as providing t weil of the receptacle with laterally ei: tended projections 4G, see Fig. 4, arranger? to largely increase the area of the exposed surimes, Wnerehy the walls of the rc* ceptncie are i'neintained et a low tempera '.fented from becoming unduly heated. of the responsive coding notion may he iess in the latter i stance than in the former, but in many instances :auch i'iesign oi cooling Ineens gives satisectorjv" results.

the provision of cooling means to dissipate tire heet generated in the vwalls of the :'eceftuc e, si'. oir 'the switch unit muy he muinuineffi 'wienin moderate dimensions anti the insuinting oil therein maintained :it its state of nl :ixiinuin effectiveness.

i, The combination, with the characteri ic mechanicui und electricail factors of :in o i circuit hren-ker, of ineens to keep down the temperature ci" the oil..

The combination, with the chui-acteristic niechunicni z d electxficni factors of un oil circuit brei "2r, of ineens to keep down the temperature of the oil, adjacent to the tank Walls.

In :in electric switch adapted for the Qontrol of alternating currents, oi :tn inclosing casing therefor, formed of magnetic material lia-ving :i tendency to heeft tine to hysteresis and eddy currents induced in the coinp: rents :intl Ineens t' :abstract iron; e Casin?.

in e ctric switch adapted ior the -riuiting currents. oi :i metallic it comlucting comi heating due nto the surrounding the current i ponente, und ineens to ufogenerated in siti casing.

adapted for the con current circuit, in- "'1g formed ot nlugef to he hcnted in;

e to erich switch, u '.cizy'oi the coohng In which sociztteil with the g.

I., 1 l l l 1 r. Au eiectric su'rtcn adopte-u ier t'ne controlof an alternating current circiiit, inn cluding an inclosing casing formed o inagnetic material adaptedfto Jrheheated by ,hysteresis and eddyA currents'iiiduced therein by the alternating nur surrounding the lcurrent conducting components of the switch, the temperature rise, due' to such heating, limiting the capacity of the switch, and means to increase the capacity of the 'switch which comprises artificial cooling meansv associated with the switch arranged to abstract heat from the casing.

8. An electric. switch adapted for the control of an alternating current circuit, including an inclosing casing therefor formed of va material adapted to beheated by the alternating y flux surrounding the current conducting components of the switch, the

tei'n'perature rise, due to such heating,.]im-

itingthe capacityof the switch, and means to increase the capacity of the switch which comprises artificial coolin means associated with the switch arrange from said casing and maintainthe temperato abstract heat ture thereof at a low value.

9. An electric switch having a casing con-` taining oil in whichsome of the components are immersed, and characterized by said casing adapted to be heated by the current carried by the switch and determining the current carrying capacity of the switch by the temperature rise, and means for increasing the current carrying capacity of the switch which comprises cooling means associated with said casing adapted to-abstract,1

heat therefrom.

10. An electric switch having a casing containing oil in which some of the components are immersed, and characterized by said casing adapted to be heated by the current carried by the switch and determining the current carrying capacity of the switch 'bythe temperature rise, and means increasing the current carrying. capacity of the switch which comprises cooling means associated with vsaid casing adapted to abstract heat therefrom, and from the oil and other switch components.

11j. An electric switch having a casing containing oil in which some of the components are immersed and characterized by;

said casingadapted -to be heated by the current carried by the switch and determining the curreiit carrying capacit of the switch by the temperature rise,an means for in- `1 creasing the current carrying capacity of the switch which comprises cooling means asso- -ciated with said casing and other switch components and adapted to abstract heat from all of them.

12. Apparatus including artificial means for maintaining a reduced temperature vand an electric switch having its circuit controlling component arranged in the iield of said means to be influenced thereby.

. name to this specification, in the I two subscribing witnesses.-

GEoReEA. BURNIiaM. i

13. An electric switch adapted for the control of an alternating currentcircuit having components thereof adapted to be heated by the current carried bythe switch, and the temperature rise dueto such heating limiting the capacity-fof the switch and means for increasing the current carrying capacity of the switch comprising artificial cooling means. associated with said components to abstract heat therefrom and main- Iponents are immersed,` and characterized: by

such oil serving to abstract heat from the components,-and means for increasing the current carrying capacity of the switch comprising cooling means associated with the switch, adapted to abstract heat from the loil and thereby maintain its temperature lrise of low value. f

16.. An electric switch comprising components adapted to be heated by the current carried by the switch, the temperature rise thereof limiting the capacity of the switch,

' an insulating, heat-absorbent iluid in which certain of said components are immersed by l which the circuit-interrupting arc is dissipatedand the heat of said components absorbed, and articial cooling means -for said insulating fluid to maintain the temperature of said {'luid at a low Value and thereby increase the current-carrying capacity of the l switch.

17. An electric switch comprising components adapted to be heated by the current carried by the switch, the temperature rise thereof limiting the capacity of the switch, an insulating, heat-absorbent fluid in which certain of -said components are immersed by which thecircuit-interrupting arc is dissipated and the heat of said 'components absorbed, said iiuid being thereby heated, and means to present cool 'arcldissipating, heatabsorbent fiuid to said components which `comprises cooling means associated with 'said fluid.

In-testimonywhereof, I have signed my presence of' Witnesses: i

HAROLD S. RAMsAY, DANIEL M. Smrrnn'i. 

